Timing of Trump's latest tariff threat against China is 'especially unfortunate': Former US deputy trade rep

"The timing is especially unfortunate," Miriam Sapiro, a former deputy and acting U.S. trade representative during the Obama administration, said after President Donald Trump threatened another $100 billion tariffs on Chinese products.

The latest development would make it more difficult for China to engage. "Either China matches this escalation, plays tit-for-tat, or it takes a high road and score significant leadership point," she said.

U.S. President Donald Trump waves as he departs from the White House on July 12, 2017 in Washington, DC.

It's unfortunate that President Donald Trump has chosen to add fuel to an already heated spat with China just as officials from both countries have signaled their willingness to negotiate to avoid escalating trade tensions, said a former deputy U.S. trade representative.

"The timing is especially unfortunate," Miriam Sapiro, a former deputy and acting U.S. trade representative during the Obama administration, told CNBC's "Squawk Box" on Friday.

"(The latest development) just makes it more difficult for the Chinese government to engage. Either China matches this escalation, plays tit-for-tat, or it takes a high road and score significant leadership point," she added.

That would heighten the prospect of a trade war between the two largest economies in the world, which would then hurt the "very U.S. companies that the White House has been trying to help," noted Sapiro, who's now managing director of Sard Verbinnen & Co's New York office.